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alizadeh-aliabadi--hamzeh
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Study of Carbon Monoxide Emission and Dispersion in Long Motorway Spaces: A Case Study of Tohid Tunnel
,
M.Sc. Thesis
Sharif University of Technology
;
Vaziri, Manouchehr
(Supervisor)
Abstract
Vehicular tunnels are very prone to excess of air pollution due to their enclosed nature. Inadequate ventilation combined with high traffic flow result in elevated concentration of vehicle-induced air pollutants, which can pose serious health hazards. This study was carried out in the longest vehicular tunnel in Tehran, locally referred to as Tohid tunnel. Traffic flow characteristics, carbon monoxide level and it's dispersion along the tunnel were investigated in this project. Data were collected in 4 days and 3 times a day, 7-8 in the morning, 11-12 and 17-18 in the evening. Measurements were conducted at fixed locations, outside the tunnel,...
Multi-rate and multi-quality of service passive optical network based on hybrid WDM/OCDM system [electronic resource]
, Article IEEE Communications Magazine ; February 2011, Volume 49, Issue 2, PP. S39-S44 ; Salehi, J. A ; Sharif University of Technology
Abstract
In this article we present a new scheme to support multirate and multi-quality-of-service transmission in passive optical networks based on a hybrid wavelength-division multiplexing/optical code-division multiplexing scheme. The idea is to use multilength variable-weight optical orthogonal codes as signature sequences of a hybrid WDM/OCDM system. To provide the requested classes of service, the code weight and code length of MLVW-OOCs are designed based on the characteristics of the requested classes of service. In order to mitigate multiple access interference, we propose to utilize a multilevel signaling technique and interference remover structure based on advanced optical logic gate...
Power quality comparison of active islanding detection methods in a single phase PV grid connected inverter
, Article IEEE International Symposium on Industrial Electronics, 5 July 2009 through 8 July 2009 ; 2009 , Pages 1852-1857 ; 9781424443499 (ISBN) ; Mokhtari, H ; Sharif University of Technology
2009
Abstract
In this paper, the power quality of a single-phase photovoltaic grid connected inverter when uses active islanding detection methods is investigated. Two main groups of these methods are analyzed in this paper. The main focus is on the output power quality of PV sources for these methods. Also the variation of output current THD, while the output power changes, is explored. The variation of output current THD is measured when the parameters of active islanding detection method are changed, and the limitation of these parameters for complying power quality standards in the nominal output power is detected. ©2009 IEEE
Formation of Plasma Electrolytic Oxidation Coating on Mg-Ti Coupl Joint with Friction stir Welding Process and Evaluation its Properties
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
Plasma electrolytic oxidation is the novel surface engineering technology that used as the low cost and eco-friendly method for improvement of corrosion resistance and wear resistance of Mg and Ti alloys. The aim of this investigation is firstly joint the Ti and Mg, then optimization of coating process condition of Ti-Mg couple for achieve the best corrosion and wear resistance of coating. For this purpose, initially Ti and Mg were joint together by friction stir welding treatment and then the effect of coating variable such as type of electrolyte, coating voltage, coating time and the concentration of the bath constitute, on the coating properties were investigated, and then the effect of...
A decentralized self-adjusting control strategy for reactive power management in an islanded multi-bus MV microgrid
, Article Canadian Journal of Electrical and Computer Engineering ; Volume 36, Issue 1 , 2013 , Pages 18-25 ; 08408688 (ISSN) ; Mokhtari, H ; Karimi, H ; Sharif University of Technology
2013
Abstract
This paper presents a decentralized self-adjusting reactive power controller for the autonomous operation of a multi-bus medium voltage (MV) microgrid. The main objective of the proposed control strategy of each distributed generation (DG) unit is to compensate the reactive power of its local loads and to share the reactive power of the nonlocal loads among itself and other DG units. The proposed control strategy includes an improved droop controller whose parameters are adjusted according to the reactive power of the local loads. A virtual inductive impedance loop is augmented to the voltage controller to enhance the steady state and transient responses of the proposed reactive power...
A new control strategy for a multi-bus MV microgrid under unbalanced conditions
, Article IEEE Transactions on Power Systems ; Volume 27, Issue 4 , 2012 , Pages 2225-2232 ; 08858950 (ISSN) ; Karimi, H ; Mokhtari, H ; Sharif University of Technology
2012
Abstract
This paper proposes a new control strategy for the islanded operation of a multi-bus medium voltage (MV) microgrid. The microgrid consists of several dispatchable electronically-coupled distributed generation (DG) units. Each DG unit supplies a local load which can be unbalanced due to the inclusion of single-phase loads. The proposed control strategy of each DG comprises a proportional resonance (PR) controller with an adjustable resonance frequency, a droop control strategy, and a negative-sequence impedance controller (NSIC). The PR and droop controllers are, respectively, used to regulate the load voltage and share the average power components among the DG units. The NSIC is used to...
Robust backstepping control of an interlink converter in a hybrid AC/DC microgrid based on feedback linearisation method
, Article International Journal of Control ; Volume 90, Issue 9 , 2017 , Pages 1990-2004 ; 00207179 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
2017
Abstract
This paper presents a robust dc-link voltage as well as a current control strategy for a bidirectional interlink converter (BIC) in a hybrid ac/dc microgrid. To enhance the dc-bus voltage control, conventional methods strive to measure and feedforward the load or source power in the dc-bus control scheme. However, the conventional feedforward-based approaches require remote measurement with communications. Moreover, conventional methods suffer from stability and performance issues, mainly due to the use of the small-signal-based control design method. To overcome these issues, in this paper, the power from DG units of the dc subgrid imposed on the BIC is considered an unmeasurable...
On maximal and minimal linear matching property
, Article Algebra and Discrete Mathematics ; Volume 15, Issue 2 , 2013 , Pages 174-178 ; 17263255 (ISSN) ; Darafsheh, M. R ; Sharif University of Technology
2013
Abstract
The matching basis in field extentions is in-troduced by S. Eliahou and C. Lecouvey in [2]. In this paper we define the minimal and maximal linear matching property for field extensions and prove that if K is not algebraically closed, then K has minimal linear matching property. In this paper we will prove that algebraic number fields have maximal linear matching property. We also give a shorter proof of a result established in [6] on the fundamental theorem of algebra
A rigorous security analysis of a decentralized electronic voting protocol in the universal composability framework
, Article Journal of Information Security and Applications ; Volume 43 , 2018 , Pages 99-109 ; 22142134 (ISSN) ; Rezaei Aliabadi, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Designing an efficient and secure electronic voting (e-voting) protocol without the presence of trusted authorities, known as decentralized voting protocols, is one of the most interesting and challenging problems in cryptography. In these protocols the outcome of the protocol is computed by voters collaborating with each other. We provide a rigorous proof of security of a decentralized e-voting protocol proposed by Khader et al. in the Universal Composability (UC) Framework. This protocol is the state-of-the-art decentralized e-voting protocol in terms of efficiency and security, whose security has only been justified against a set of desired properties required in e-voting protocols. For...
Primary and secondary frequency control in an autonomous microgrid supported by a load-shedding strategy
, Article PEDSTC 2013 - 4th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2013 , Pages 282-287 ; 9781467344845 (ISBN) ; Ameli, M. T ; Hamzeh, M ; Sharif University of Technology
2013
Abstract
This paper proposes a frequency control strategy for an islanded inverter-based microgrid which based on the priority of supply, has got two distinct types of loads, namely sensitive and deferrable. The proposed strategy consists of primary and secondary levels of generation control supported by a loadshedding scheme. The primary control regulates the output power of the distributed generator (DG) units to be proportional to their ratings while secondary control has got the duty of frequency restoration after each load change. Functionality of these two levels is demonstrated to be independent of each other. Both controls are in distributed forms which have no need of communication...
Robust backstepping control of an interlink converter in a hybrid AC/DC microgrid based on feedback linearisation method
, Article International Journal of Control ; 2016 , Pages 1-15 ; 00207179 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
This paper presents a robust dc-link voltage as well as a current control strategy for a bidirectional interlink converter (BIC) in a hybrid ac/dc microgrid. To enhance the dc-bus voltage control, conventional methods strive to measure and feedforward the load or source power in the dc-bus control scheme. However, the conventional feedforward-based approaches require remote measurement with communications. Moreover, conventional methods suffer from stability and performance issues, mainly due to the use of the small-signal-based control design method. To overcome these issues, in this paper, the power from DG units of the dc subgrid imposed on the BIC is considered an unmeasurable...
A backstepping high-order sliding mode voltage control strategy for an islanded microgrid with harmonic/interharmonic loads
, Article Control Engineering Practice ; Volume 58 , 2017 , Pages 150-160 ; 09670661 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
This paper presents a new nonlinear voltage control strategy based on backstepping control and a high-order sliding mode differentiator for an islanded microgrid. The microgrid consists of multiple distributed generation (DG) units with an arbitrary configuration that can be parametrically uncertain or topologically unknown. The proposed controller robustly regulates the microgrid voltages in the presence of parametric uncertainties, unmodeled dynamics, load imbalances, and nonlinear loads with harmonic/interharmonic currents. In contrast to existing methods, the controller does not need to know the frequency of harmonic and interharmonic current of microgrid loads that lead to the reduction...
Distributed robust finite-time secondary voltage and frequency control of islanded microgrids
, Article IEEE Transactions on Power Systems ; Volume 32, Issue 5 , 2017 , Pages 3648-3659 ; 08858950 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
2017
Abstract
This paper presents a distributed, robust, finite-time secondary control for both voltage and frequency restoration of an islanded microgrid with droop-controlled inverter-based distributed generators (DGs). The distributed cooperative secondary control is fully distributed (i.e., uses only the information of neighboring DGs that can communicate with one another through a sparse communication network). In contrast to existing distributed methods that require a detailed model of the system (such as line impedances, loads, other DG units parameters, and even the microgrid configuration, which are practically unknown), the proposed protocols are synthesized by considering the unmodeled...
A robust backstepping high-order sliding mode control strategy for grid-connected DG units with harmonic/interharmonic current compensation capability
, Article IEEE Transactions on Sustainable Energy ; Volume 8, Issue 2 , 2017 , Pages 561-572 ; 19493029 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
This paper presents a new nonlinear current control strategy based on backstepping control and high-order sliding mode differentiator in order to employ distributed generation (DG) unit interfacing converters to actively compensate harmonics/interharmonics of local loads. The converter-based DG unit is connected to a weak grid (with uncertain impedance) and local load (that can be parametrically uncertain and topologically unknown) through an LCL filter. The proposed strategy robustly regulates the inverter output currents and delivers pure sinusoidal, three-phase balanced currents to the grid. The new controller demonstrates the robust performance and robust stability of the DG unit system...
Fully distributed cooperative secondary frequency and voltage control of islanded microgrids
, Article IEEE Transactions on Energy Conversion ; Volume 32, Issue 2 , 2017 , Pages 675-685 ; 08858969 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
2017
Abstract
This paper proposes a new distributed cooperative secondary control for both frequency and voltage restoration of an islanded microgrid with droop-controlled, inverter-based distributed generations (DGs). Existing distributed methods commonly design secondary control based on the minimum real part of the nonzero Laplacian matrix eigenvalues related to the microgrid communication graph, which, however, is global information. In contrast to the existing distributed methods, in this paper we design a fully distributed adaptive control based on the dynamic model of DG units and on information from neighboring units. Therefore, the proposed control scheme increases the system reliability,...
Robust tuning of transient droop gains based on kharitonov's stability theorem in droopcontrolled microgrids
, Article IET Generation, Transmission and Distribution ; Volume 12, Issue 14 , 2018 , Pages 3495-3501 ; 17518687 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
2018
Abstract
This study addresses the robust stability analysis for an islanded microgrid with droop-controlled inverter-based distributed generators (DGs). Owing to large load changes, microgrid structure reconfiguration, and higher-power demands, the low-frequency (LF) dominant modes of a microgrid stir toward unstable zone and make the system more oscillatory or even unstable. In this study, a robust two-degree-of-freedom (2DOF) decentralised droop controller, which is the combination of the conventional droop with a robust transient droop function, is utilised for each inverter-based DG unit. Unlike conventional tuning of 2DOF droop controllers, a new design procedure is proposed to robustly...
Synthesis and Characterization of Cobalte Ferrite and Nickel Ferrite Nanocatalysts and Their Application in the C-X Bond Activation Reaction
, M.Sc. Thesis Sharif University of Technology ; Matloubi Moghaddam, Firouz (Supervisor)
Abstract
Nowadays application of metallic catalysts in many of the organic reactions has been developed; therefore, different types of catalysts have been produced and used. In this way, in the first part of this thesis magnetic cobalt ferrite and nickel ferrite nanocatalysts were synthesized using co-precipitation method and their activity as catalyst was investigated in C-O bond formation reaction. This reaction was carried out between different types of aryl alcohols and aryl halides with good to excellent yields. The results showed that using N,N-dimethyl formamide as solvent, potassium carbonate as base and 5mol% of nanocatalysts at 80°C are the optimized condition for this reaction. In the...
Simultaneous Analysis of Aliphatic Alcohols Mixtures Using an Electronic Nose Based on Nano/Microstructured Conducting Polypyrrole Film Prepared by Catalytic Electropolymerization on Cu/Au Interdigital Electrodes Using Multivariate Calibration
, Article IEEE Sensors Journal ; Volume 16, Issue 2 , 2016 , Pages 418-425 ; 1530437X (ISSN) ; Babaei, M ; Alizadeh, M. S ; Mani Varnosfaderani, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, nano/microstructured-conducting polypyrrole has been prepared on Cu/Au interdigital electrode surfaces by using constant potential amperometry technique. The Fe(II) ions were used as catalyst and X = ClO4 -, pTs-, Cl-, TCA-, DS-, DBS- was implemented as anion dopants. The morphologies of the films were investigated by field emission scanning electron microscope. A remarkable dependence was observed between the type of anion dopant and the morphology of polypyrrole (PPy). The sensing behavior of the PPy-X sensor has been studied toward acetone, methanol, ethanol, 1-propanol, 2-propanol, nitromethane, propylamine, pyridine, and gas mixtures of aliphatic alcohols. The responses...
Control of a microgrid with unbalanced loads using virtual negative-sequence impedance loop
, Article PEDSTC 2014 - 5th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2014 , p. 78-83 ; Karimi, H ; Mokhtari, H ; Mahseredjian, J ; Sharif University of Technology
2014
Abstract
This paper presents an effective control strategy for autonomous operation of a multi-bus medium voltage (MV) microgrid (MG) consisting of several dispatchable distributed generation (DG) units. Each electronically-coupled DG unit supplies the loads which can be unbalanced due to the inclusion of single-phase loads. The proportional resonance (PR) and droop controllers are, respectively, used to regulate the load voltage and share the average powers among the DG units. The virtual negative-sequence impedance controller (VNSIC) is proposed to effectively compensate the negative-sequence currents of the unbalanced loads. Moreover, the VNSIC minimizes the negative-sequence currents in the MV...